Biden and Ukraine President Zelenskyy speak as U.S. warns of potential Russian invasion

President Joe Biden spoke with Ukrainian President Volodymyr Zelenskyy on Sunday after the White House warned that Russia could launch an invasion as early as this week. CBS News foreign correspondent Imtiaz Tyab reports, then joins CBS News' Lana Zak with more from Kyiv. CBS News Streaming Network is the premier 24/7 anchored streaming news service from CBS News and Stations, available free to everyone with access to the Internet. The CBS News Streaming Network is your destination for breaking news, live events and original reporting locally, nationally and around the globe. Launched in November 2014 as CBSN, the CBS News Streaming Network is available live in 91 countries and on 30 digital platforms and apps, as well as on CBSNews.com and Paramount+. Subscribe to the CBS News YouTube channel:    / cbsnews   Watch CBS News: https://cbsn.ws/1PlLpZ7c Download the CBS News app: https://cbsn.ws/1Xb1WC8 Follow CBS News on Instagram:   / cbsnews   Like CBS News on Facebook:   / cbsnews   Follow CBS News on Twitter:   / cbsnews   Subscribe to our newsletters: https://cbsn.ws/1RqHw7T Try Paramount+ free: https://bit.ly/2OiW1kZ For video licensing inquiries, contact: [email protected]